PDR for Herbal Medicines

HERBAL MONOGRAPHS WILD YAM /817

varieties with high erucic acid content (40 to 50%) are no

longer cultivated (reduction of the erucic acid content in the

Common Market countries to below 5%)

Sterols: beta-sitosterol, campesterol, brassicasterol, estered

to some extent

EFFECTS

Rapeseed oil, when ingested in high dosages over an

extended period of time, is cardiotoxic. The drug is chiefly

used as a substitute for olive oil and in the manufacture of

salves and liniments.

INDICATIONS AND USAGE

No medicinal indications

PRECAUTIONS AND ADVERSE REACTIONS:

No health hazards are known in conjunction with the proper

administration of designated therapeutic dosages of the oil,

which is low on erucic acid.

DOSAGE

Storage: Store in the dark, in well-filled containers.

LITERATURE

Hansel R, Keller K, Rimpler H, Schneider G (Ed), Hagers

Handbuch der Pharmazeutischen Praxis, 5. Aufl., Bde 4-6

(Drogen), Springer Verlag Berlin, Heidelberg, New York, 1992-

1994.

Inamori Y, Muro C, Sajima E, Katagiri M, Okamoto Y, Tanaka

H, Sakagami Y, Tsujibo H, Biological activity of purpurogallin.

Biosci Biotechnol Biochem, 61:890-2, 1997 May.

Wild Yam

Dioscorea villosa

TRADE NAMES

Wild Yam Extract, Mexican Wild Yam Power, Wild Yam,

Wild Yam Root & Rhizome Extract, Wild Yam Root

(available from numerous manufacturers and as a combina-

tion product)

DESCRIPTION

Medicinal Parts: The medicinal part 4s the dried rhizome

with the roots.

Flower and Fruit: The plant has small greenish-yellow

flowers. The male flowers are in drooping panicles; the

female ones in drooping spicate racemes.

Leaves, Stem and Root: Dioscorea villosa is a perennial vine.
It has a pale brown, cylindrical, twisted, tuberous rhizome
and a thin, woolly, reddish-brown stem that measures up to
12 m long. The leaves are broadly ovate, usually alternating,
cordate and 6 to 14 cm long. The upper surface of the leaves |

is glabrous and they are pubescent beneath. The fracture is

short and hard.

Characteristics: The taste is insipid at first, then acrid. The

leaves are odorless.

Habitat: The plant is indigenous to the Southern U.S. and

Canada. It is now widely cultivated in many parts of the

world in tropical, subtropical and temperate regions.

Production: Wild Yam root is the root and rhizome of

Dioscorea villosa.

Other Names: China Root, Colic Root. Devil's Bones,

Rheumatism Root, Yuma

ACTIONS AND PHARMACOLOGY

COMPOUNDS

Saponins: including dioscin (aglycone diosgenin)

Isoquimiclidine alkaloids: including dioscorin

Pyrridinal alkaloids: including dioscorine

EFFECTS

Wild Yam has an antispasmodic, and a mild diaphoretic

effect. The root of the plant is used as a precursor for

manufacturing progesterone and estrogen. Though the

diosgenin componant has been promoted as a "natural

progesterone," diosgenin does not have any progesterone-

like effects. The body does not convert diosgenin into

estrogen or any other steroid.

Anti-Inflammatory Effect:

In the rat model, diosgenin has been found to decrease the

intestinal inflammation that accompanies indomethacin use

(Yamada et al, 1997).

Biliary Cholesterol Elimination Effect:

Diosgenin has been shown to markedly increase the biliary

output of cholesterol and lipid lamellar structures in the rat

model. Diosgenin also has a cytoprotective effect on the rat

liver that is subjected to obstructive cholestasis (Accatino et

al, 1998).

Estrogenic Effect:

Diosgenin has been found to have an estrogenic effect on

mouse mammary epithelium. Ovariectomized mice that

received diosgenin (sc) at dosage levels between 20 and 40

mg/kg for 15 days had significant increases in mammary

development scores. When administered estrogen and

diosgenin, an augmentation of the estrogenic effect was

recorded (Aradhana et al, 1992).

INDICATIONS AND USAGE

Unproven Uses: Wild Yam is used for rheumatic conditions,

gallbladder colic, dysmenorrhea and cramps.